Abstract
The term conjugated linoleic acid (CLA) refers to the various positional and geometric isomers of linoleic acid (18:2 n-6). The natural dietary sources for CLA are dairy products and meats. CLA has received a great deal of attention as a potential anti-obesity, anti-carcinogenic, and anti-atherosclerotic agent. The purpose of this study was to examine various adiposity effects of CLA supplementation in combination with two types of high-fat diets, using weanling pigs as a model. Sorghum-based diets were supplemented with either 15% beef tallow or corn oil, or 12% tallow or corn oil plus 3% CLA. Six pigs were assigned to each diet group, with the feeding trial lasting 35 days. Weights of tissue components from dissected rib sections displayed no differences between diets. Adipose tissue cellularity measures from two sites in the rib sections showed significant differences, but there were no dietary effects except in cell density and estimated total adipocytes per rib section, where tallow + CLA-fed pigs had significantly more cells than both corn-oil-fed groups. CLA intake caused significant accumulation of CLA in membrane, microsome, and storage subcellular compartments in both adipose and muscle tissue, with the microsomes containing the least CLA. There were significant modifications to percentages of total fatty acids. Reductions in total monounsaturated fatty acids (MUFA) with CLA intake were similar to actual dietary intake due to dilution of MUFA by CLA. Total saturated fatty acids (SFA) were increased by CLA. The resulting MUFA/SFA ratio dropped 23% in tallow-fed and 34% in corn-oil-fed pigs when CLA was present (tallow: 0.83; tallow + CLA: 0.64; corn oil: 0.91; corn oil + CLA: 0.60). In conclusion, these results disagree with body composition changes reported in numerous studies in many animal species. Our data are substantially similar to changes in fatty acid distributions found in many of these studies. Additionally, we did not find enrichment of CLA in adipose and muscle microsomes relative to the membrane or storage subfractions.
Demaree, Scott R (2001). Effects of conjugated linoleic acid feeding on adiposity in post-weanling pigs. Master's thesis, Texas A&M University. Available electronically from
https : / /hdl .handle .net /1969 .1 /ETD -TAMU -2001 -THESIS -D482.